21020248 has 16 divisors (see below), whose sum is σ = 39889080. Its totient is φ = 10383168.

The previous prime is 21020239. The next prime is 21020267. The reversal of 21020248 is 84202012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15165 + ... + 16492.

Almost surely, 2^21020248 is an apocalyptic number.

It is an amenable number.

21020248 is a deficient number, since it is larger than the sum of its proper divisors (18868832).

21020248 is a wasteful number, since it uses less digits than its factorization.

21020248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31746 (or 31742 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 21020248 is about 4584.7844006016. The cubic root of 21020248 is about 275.9810601020.

The spelling of 21020248 in words is "twenty-one million, twenty thousand, two hundred forty-eight".